1. a person who is physically weak or lacks strength
2. a person who lacks courage, determination, or willpower

Examples

• The bully picked on him because he thought he was a weakling.
• She proved she was no weakling by completing the marathon.
• Don’t call yourself a weakling just because you need help sometimes.
• The coach turned the weakling into a strong athlete through training.
• He felt like a weakling for backing down from the argument.
• The weakling struggled to lift even the lightest weights.